Hello Ifthar,
I think you should concentrate more on the combustion ratio to control the oxygen content in the molten copper also at the same time see to it that because of rich combustion ratio, the hydrocarbons generated in the molten metal will not effect the sound casting. If there are excess hydrocarbons in molten metal than it will lead to form blow holes in the cast bar. Overheating of the molten metal with a rich combustion ratio flame will reduce the oxygen content and if you can churn or stir the metal than oxygen level will go down faster. If it is at all possible than try to churn the molten metal with the help of racking tool.
Milind Haldankar
Production Manager
ACL Metals & Alloys Pvt Ltd, Sri Lanka.
This email address is being protected from spambots. You need JavaScript enabled to view it.